Pre- and postoperative heart rate variability and vagus nerve stimulation in patients with drug-resistant epilepsy - A meta-analysis

Author: Mao-Lin Wu1, Dan-Mei Hu1, Jun-Jie Wang2, Xiao-Lei Liu1, Lei Liu3, Yuan Li4, Wei Jing5
Affiliation: <sup>1</sup> Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China; Key Laboratory of Cellular Physiology (Shanxi Medical University), Ministry of Education, Taiyuan, Shanxi, China. <sup>2</sup> Qingdao University, Qingdao, Shandong, China. <sup>3</sup> University of Virginia School of Medicine, Charlottesville, Virginia, USA. <sup>4</sup> Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China. Electronic address: lishenjingyuan@163.com. <sup>5</sup> Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, Shanxi, China; Key Laboratory of Cellular Physiology (Shanxi Medical University), Ministry of Education, Taiyuan, Shanxi, China. Electronic address: jingweistar@163.com.
Conference/Journal: Epilepsy Behav
Date published: 2021 Aug 18
Other: Volume ID: 123 , Pages: 108247 , Special Notes: doi: 10.1016/j.yebeh.2021.108247. , Word Count: 321


Objective:
The effect of vagus nerve stimulation (VNS), an important auxiliary therapy for treating drug-resistant epilepsy (DRE), on autonomic nerve function is still controversial. Heart rate variability is a widely used indicator of autonomic nerve function. To clarify the relationship between VNS and heart rate variability (HRV), we performed a meta-analysis to systematically evaluate the effect of VNS on HRV in patients with epilepsy.

Methods:
We performed a systematic review by searching the following online databases: PubMed, Web of Science, EMBASE and the Cochrane Library. The key search terms were "vagal nerve stimulation," "epilepsy" and "heart rate variability". Other features of VNS in patients with epilepsy include postoperative changes in low-frequency (LF), high-frequency (HF) and low-frequency/high-frequency (LF/HF) heart rate variability, which were used as evaluation indices, and the Newcastle-Ottawa Quality Assessment Scale and Stata 14.0 statistical software were used for literature quality evaluation and meta-analysis.

Results:
Twelve studies published in English were obtained, and 229 patients with epilepsy who underwent VNS were ultimately included after elimination of duplicate articles and those that did not meet the inclusion criteria. Regarding LF heart rate variability, in the response subgroup, patients with DRE with VNS presented a lower value (-0.58) before surgery than after surgery, with a 95% confidence interval (CI) ranging from -1.00 to -0.15. For HF heart rate variability, patients with DRE with VNS had a lower value (-0.45) before surgery than after surgery in the response subgroup, with a 95% CI ranging from -0.74 to -0.17. No differences were found for LF/HF values or the LF and HF values of other subgroups.

Conclusion:
VNS has little effect on the balance of sympathetic and parasympathetic nerve activity and would not be expected to cause cardiovascular autonomic dysfunction in patients with DRE. For patients with DRE, VNS can control seizures and has little effect on autonomic nervous function.

Keywords: Autonomic nerve function; Epilepsy; Heart rate variability; Meta-analysis; Vagal nerve stimulation.

PMID: 34418640 DOI: 10.1016/j.yebeh.2021.108247